Lets put this in perspective. A continuous 1 gigawatt draw is enough energy to boil off 1.3 million liters per hour. Assuming a generous 350 liters per person per day that's the equivalent of 90k people.
If you don't actually boil it and instead return only lukewarm water you're looking at something like 15x more (I don't know the exact factor) due to how large the heat of vaporization is.
How exactly are they supposed to return (ballpark) 1 million people worth of water to the utility company? Let's again put this in perspective. The entire Seattle metropolitan area hosts ~4.1 million people. The entire state of Florida is only 23.5 million. This is an absurd amount of water we're taking about here.
